The 38-year-old victim was driving on Gelderd Road towards the ring road when he saw a woman who appeared to be in distress.
He pulled over close to the road’s Porsche car showroom with the intention of going to help her but came under attack from two men.
They smashed the windscreen of his red Toyota Auris and then assaulted him and stole his mobile phone.
The attackers left the scene in what was described as a “powerful” silver-coloured car.
The victim managed to make his way to Tong Road in Armley, where he found a phone box and dialled 999.
He received treatment in intensive care for serious head and face injuries and is continuing to recover in hospital.
The incident happened between 10.30pm and 11.40pm on Tuesday, February 16.
Detectives last night arrested two men, aged 24 and 36, and a 20-year-old woman in the Farnley area last night on suspicion of robbery. The three, who are all Polish nationals, are currently in custody.
Officers have also recovered a grey Jaguar X-type car that is undergoing forensic examination.